Prego?

My last period was Dec 25th-29th I’m on a 28 day cycle i had sex on Dec. 31st i ovulated Jan. 6-12th i had sex on the 7th-9th and my ovulation day was on the 11th my period if you count 28 days would’ve been on the 22nd but my tracker says 25th i haven’t had a period and it’s almost the end of the month. If i am pregnant i would be about 2 weeks maybe ? Is that far enough for a at home test to detect ?